Excavating machine with stowable discharge conveyor

ABSTRACT

An excavating machine includes a discharge conveyor which is movable (1) from an operative position in which an inlet end thereof is located directly under the outlet end of an associated loading conveyor (2) to a transport position in which the discharge conveyor extends substantially in parallel with the loading conveyor and in which the discharge end thereof is located between the inlet and discharge ends of the loading conveyor--thereby maintaining the discharge conveyor within the dimensional confines of the vehicle on which it is mounted. Movement of the discharge conveyor from its operative position to its stowed or transport position is facilitated by a support assembly including a slide and a turntable assembly. The slide includes a base which is mounted on rails or the like so as to move laterally with respect to the chassis, and the turntable assembly supports the discharge conveyor on the base for rotation about a vertical axis. By mounting the turntable assembly on a sliding base in this manner, 270° rotation of the discharge conveyor is possible without interference from the loading conveyor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to excavating machines and, more particularly,relates to self-propelled excavating machines having a vehicle, adigging implement mounted on the vehicle, and a stowable dischargeconveyor which is mounted on the vehicle and which is movable from anoperative position in which the discharge conveyor discharges excavatedmaterials into a truck to a transport position in which the dischargeconveyor is confined within the dimensional confines of the vehicle.

2. Discussion of the Related Art

Excavating machines such as rock saws, chain trenchers, and road minerstypically comprise a self-propelled vehicle having a digging implementmounted on the rear end thereof which excavates soil, rock, ore, orother materials as the vehicle travels in a forward direction. Diggingimplements have traditionally discharged materials on the ground infront of or beside the digging implement on the assumption that theexcavated materials would be used as backfill for the trench. However,in recent times, governmental regulations and other considerations haverequired that the excavated materials be removed from the work site andthat "clean" backfill be brought in from other sources. Removingmaterials excavated by traditional excavating machines requires that thematerials be retrieved either manually or by a front-end loader or thelike after the trenching operation is complete. The cost of suchsubsequent retrieval, coupled with the difficulty of retrieving allexcavated materials without at least some of the materials falling backinto the trench, has led increasingly to a demand for excavatingmachines which discharge excavated materials directly onto a truckpositioned in front of or beside the vehicle.

A particularly attractive arrangement for conveying excavated materialsto a truck from a digging implement is a so-called centerline conveyorassembly positioned on or near a longitudinal centerline of the vehicle.The typical centerline conveyor assembly includes a loading conveyor anda discharge conveyor. The loading conveyor receives excavated materialsfrom the digging implement (either directly or indirectly via one ormore intervening lateral conveyors) and conveys the excavated materialsto a discharge end thereof located in the vicinity of the front end ofthe vehicle. The discharge conveyor has an inlet end positioned underthe discharge end of the loading conveyor and extends forwardly from thefront end of the vehicle to discharge excavated materials into a truckfrom a discharge end thereof. The typical discharge conveyor isswingable on a turntable or shaft so as to be capable of dischargingmaterials onto a truck positioned on either side of the vehicle.

One disadvantage of discharge conveyors is that, in most instances, theyextend ten feet or more in front of the excavating vehicle when in theirlongitudinally-centered position, rendering the overall length of theexcavating machine unacceptable for transport. This problem could bealleviated by stowing the discharge conveyor, e.g., by swinging thedischarge conveyor to the side of the loading conveyor. However, onlylimited side-to-side movement is possible (typically in an arc of about180° extending 90° from each side of the longitudinal centerline of thevehicle) due to potential interference from the loading conveyor. Thislimited movement may reduce the overall length of the excavatingmachine, but unacceptably increases its width. Accordingly, transport ofexcavating machines having discharge conveyors has traditionallyrequired the removal or at least partial disassembly of the dischargeconveyors prior to transport.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a stowabledischarge conveyor for an excavating machine which is movable (1) froman operative position in which it is capable of discharging excavatedmaterials into a truck located either in front of or to either side ofthe excavating machine, (2) to a transport position in which it ismaintained within the dimensional confines of the vehicle on which it ismounted.

Another object of the invention is to provide an excavating machine thedischarge conveyor of which has the characteristics described above andwhich has a vertical axis of rotation which is locatable on thelongitudinal centerline of the associated loading conveyor so as to becapable of extending equidistantly to either side of the loadingconveyor, thereby facilitating discharge into trucks located on eitherside of the vehicle.

Still another object of the invention is to provide an excavatingmachine having a discharge conveyor which has one or more of thecharacteristics described above and which is relatively simple andinexpensive to install and operate.

In accordance with a first aspect of the invention, these and otherobjects are achieved by providing an excavating machine comprising aportable chassis having first and second longitudinal ends, a diggingimplement mounted on the first end of the chassis, a loading conveyor,and a discharge conveyor. The loading conveyor extends longitudinally ofthe chassis and has an inlet end which receives excavated materials fromthe digging implement and a discharge end which is located in thevicinity of the second end of the chassis. The discharge conveyor has aninlet end which receives the excavated materials from the loadingconveyor and has a discharge end. The discharge conveyor is movable (1)from an operative position in which the inlet end thereof is locateddirectly under the discharge end of the loading conveyor (2) to atransport position (a) in which the discharge conveyor extendssubstantially in parallel with the loading conveyor and (b) in which thedischarge end of the discharge conveyor is located between the inlet anddischarge ends of the loading conveyor.

A preferred mechanism for moving the discharge conveyor as describedabove is a support assembly which supports the discharge conveyor on thechassis. The support assembly include a base which is movable laterallywith respect to the chassis, and a turntable assembly which supports thedischarge conveyor on the base for rotation about a vertical axis. Thebase is located (1) in a first position located on a longitudinalcenterline of the loading conveyor when the discharge conveyor is in theoperative position and (2) in a second position which is offsetlaterally from the longitudinal centerline when the discharge conveyoris in the transport position. The support assembly also preferablypresents rails extending transversely of the chassis such that the baseis slidably supported on the rails. A hydraulic cylinder (1) isconnected to the base and to the frame support and (2) drives the baseto slide along the rails from the first position to the second position.

Preferably, in order to further facilitate transport, the loadingconveyor is pivotable about a horizontal axis (1) to raise the inlet endthereof from a lowered operative position to a raised transport positionand (2) to lower the discharge end thereof from a raised operativeposition to a transverse position below a level of the inlet end of thedischarge conveyor.

Yet another object of the invention is to provide a simple and effectivemethod of moving a discharge conveyor of an excavating machine from anoperative position to a stowed or transport position in which thedischarge conveyor is maintained within the dimensional confines of thevehicle on which it is mounted.

Yet another object of the invention is to provide a method of excavatingmaterials using an excavating machine and of stowing a dischargeconveyor of the machine within the dimensional confines of the vehicleon which it is mounted for transport.

In accordance with another aspect of the invention, these and otherobjects are achieved by providing a method comprising providing anexcavating machine, operating the machine, and then preparing theexcavating machine for transport. The providing step comprises providinga machine having (1) a portable chassis having first and secondlongitudinal ends, (2) an excavating machine mounted on the first end ofthe chassis, (3) a loading conveyor extending longitudinally of thechassis, the loading conveyor having an inlet end located in thevicinity of the first end of the chassis and having a discharge endlocated in the vicinity of the second end of the chassis, and (4) adischarge conveyor having inlet and discharge ends. The operating stepcomprises placing the excavating machine in an operative position inwhich the discharge end of the loading conveyor is located above theinlet end of the discharge conveyor and in which the inlet end of thedischarge conveyor is located on a longitudinal centerline of theloading conveyor. Then, while the excavating machine is in the operativeposition, (1) materials are excavated using the digging implement, (2)the excavated materials are fed to the discharge conveyor using theloading conveyor, and (3) the excavated materials are discharged fromthe excavating machine using the discharge conveyor. The step ofpreparing the machine for transport comprises moving the dischargeconveyor laterally away from the longitudinal centerline of the loadingconveyor, and then rotating the discharge conveyor into a position inwhich the discharge conveyor extends substantially in parallel with theloading conveyor and in which the discharge end thereof is locatedbetween the inlet and discharge ends of the loading conveyor.

Preferably, the moving step comprises sliding the discharge conveyoralong rails extending transversely of the chassis, and the rotating stepcomprises driving a table to rotate about a bearing which is supportedon a base, the table supporting the inlet end of the discharge conveyor,and the base being slidably mounted on the rails.

In order to facilitate access by a truck during operation of theexcavating machine, a further step preferably comprises rotating thedischarge conveyor about a vertical axis (1) from a first position inwhich the discharge conveyor extends laterally over a first side of thechassis and the discharge end thereof is positioned a designateddistance from a longitudinal centerline of the loading conveyor, (2) toa second position in which the discharge conveyor extends laterally overa second side of the chassis and the discharge end thereof is positionedthe designated distance from the longitudinal centerline of the loadingconveyor.

Finally, the step of preparing the excavating machine for transportpreferably further comprises pivoting the loading conveyor about ahorizonal axis, thereby raising the inlet end of the loading conveyorfrom a lowered operative position to a raised transport position andlowering the discharge end below a level of the inlet end of thedischarge conveyor.

Other objects, features, and advantages of the present invention willbecome apparent to those skilled in the art from the following detaileddescription and the accompanying drawings. It should be understood,however, that the detailed description and specific examples, whileindicating preferred embodiments of the present invention, are given byway of illustration and not of limitation. Many changes andmodifications may be made within the scope of the present inventionwithout departing from the spirit thereof, and the invention includesall such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred exemplary embodiment of the invention is illustrated in theaccompanying drawings in which like reference numerals represent likeparts throughout, and in which:

FIG. 1 is a perspective view of an excavating machine employing aconveyor assembly constructed in accordance with a preferred embodimentof the invention and illustrating the excavating machine in an operativeposition;

FIG. 2 is a partially cut away side elevation view of the excavatingmachine of FIG. 1, illustrating the excavating machine in an operativeposition;

FIG. 3 is a top plan view of the excavating machine of FIGS. 1 and 2,and illustrating in phantom lines side-to-side motion of the dischargeconveyor thereof;

FIG. 4 is a partially cut away side elevation view of the excavatingmachine of FIGS. 1-3, illustrating the excavating machine in a transportposition;

FIG. 5 is a front end elevation view of the excavating machine of FIGS.1-4, illustrating the conveyor assembly in a stowed or transportposition;

FIGS. 6-8 schematically illustrate the operation of a slide and aturntable assembly supporting the discharge conveyor on the vehicle;

FIG. 9 is a sectional elevation view taken along the lines 9--9 of FIG.8; and

FIG. 10 is an exploded perspective view of the turntable and slideassemblies of FIGS. 6-9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 1. Resume

Pursuant to the invention, an excavating machine is provided having adischarge conveyor which is movable (1) from an operative position inwhich an inlet end thereof is located directly under the outlet end ofan associated loading conveyor (2) to a transport position in which thedischarge conveyor extends substantially in parallel with the loadingconveyor and in which the discharge end thereof is located between theinlet and discharge ends of the loading conveyor--thereby maintainingthe discharge conveyor within the dimensional confines of the vehicle onwhich it is mounted. Movement of the discharge conveyor from itsoperative position to its stowed or transport position is facilitated bya support assembly including a slide and a turntable assembly. The slideincludes a base which is mounted on rails or the like so as to movelaterally with respect to the chassis, and the turntable assemblysupports the discharge conveyor on the base for rotation about avertical axis. By mounting the turntable assembly on a sliding base inthis manner, 270° rotation of the discharge conveyor is possible withoutinterference from the loading conveyor.

2. System Overview

Referring now to the drawings and initially to FIGS. 1-5 in particular,an excavating machine 10 with which the invention can be employedincludes a self-propelled vehicle 12, a digging implement 14 mounted onand extending rearwardly from the longitudinal rear end of the vehicle12, and a conveyor assembly 16 mounted on the vehicle 12 in front of thedigging implement 14. The vehicle 12 includes a chassis 18 mounted ontreads 20 for movement along the ground in a direction of travelindicated by the arrow 22 in FIG. 1. Mounted on the chassis 18 are aframe assembly 24, an operator's cab 26, and an engine 28.

The digging implement 14 may comprise any suitable cutting or trenchingdevice, and, in the illustrated embodiment, comprises a rock sawassembly mounted on the frame assembly 24 by a carriage 30. Morespecifically, a mast 32 is located on the rear end of frame assembly 24,and the carriage 30 is slidably mounted on rails 34 of the mast 32.Carriage 30 can be raised and lowered with respect to the mast 32 bymeans of hydraulic cylinders 36 to selectively raise and lower the rocksaw assembly 14 between the lowered, operative position illustrated inFIGS. 1-3 to the raised, transport position illustrated in FIG. 4. Therock saw assembly 14 includes a rotary toothed cutting wheel 38 drivento rotate by a hydrostatic motor 40 powered by engine 28. A housing 42rotatably supports the cutting wheel 38 and is pivotally mounted on thecarriage 30 at a horizontal pivot axis 44. The housing 42 is pivotedabout the axis 44 by a pair of hydraulic cylinders 46 each connected tothe mast 32 and to an upper portion of the housing 42. A rear shield 48,pivotable about the housing 42 via operation of hydraulic cylinders 50,preferably, but not necessarily, encases the rear end of the cuttingwheel 38.

The conveyor assembly 16 could be positioned to a side of the vehicle 12and receive materials from the digging implement via one or more lateralconveyors. In the preferred and illustrated embodiment, however, theconveyor assembly 16 is mounted on or near the longitudinal centerlineof the vehicle 12 and receives excavated materials directly from thedigging implement 14 in order to simplify construction and to reduce theoverall width of the excavating machine 10. The conveyor assembly 16includes a rear loading conveyor 52 and a front discharge conveyor 54.Both the loading conveyor 52 and the discharge conveyor 54 arepreferably hydrostatically-driven drag-slat conveyors the motors forwhich are powered by the engine 28. The loading conveyor 52 is pivotallymounted on the frame assembly 24 via a front pivot mount 56 and rearhydraulic cylinders 58 for reasons which will become apparent below andis inclined upwardly and forwardly from a rear inlet end 60 positionedadjacent the digging implement 14 to a front discharge end 62 positionedin the vicinity of the front end of the vehicle 12.

3. Construction of Discharge Conveyor and Support Assembly

The discharge conveyor 54 is designed to be movable from an operativeposition in which an inlet end thereof 64 is positioned directly underthe longitudinal centerline of the loading conveyor 52 to a stowed ortransport position in which the entire discharge conveyor 54 ismaintained substantially within the dimensional confines of the vehicle12. The discharge conveyor 54 is also designed to swing from side toside as illustrated in FIG. 3 when in its operative position so as topermit the discharge of excavated materials from an outlet end 66thereof into a truck T (FIG. 1 ) located either in front of orequidistantly to either side of the vehicle 12. To this end, the inletend 64 of the discharge conveyor 54 is mounted on the chassis 18 by asupport assembly 68 which includes a support frame 70, a slide 72, and aturntable assembly 74.

Referring to FIGS. 5-10, the support frame 70 includes a horizontalplate 76 mounted on the chassis 18 by a pair of laterally-spacedvertical front struts 78 and by a corresponding pair of laterally-spacedinclined rear struts 80. Opposed edge portions of the plate 76 formrails 82 extending transversely of the chassis 18. These rails 82cooperate with a corresponding base 84 to form the slide 72.Specifically, a pair of L-shaped brackets 86 depend from the lowersurface of the base 84. A pair of bars 90 and 92 are mounted on theupper surface of the plate 76 and the lower surface of the base 84,respectively, in a facing relationship with one another. The rails 82are slidably clamped between the horizontal lower legs of brackets 86 attheir lower surfaces and bars 90 and 92 and their upper surfaces. Aplurality of L-shaped bars 88 extend transversely with respect to thebrackets 86 to reenforce the brackets 86. Sliding movement of the base84 along the rails 82 is effected via a pair of hydraulic cylinders 94each of which is pivotally connected to an ear 96 on the plate 76 at itscylinder end and to a corresponding ear 98 on the base 84 at its rodend.

The turntable assembly 74 comprises but one of many devices capable of(1) swinging the discharge conveyor 54 from side to side duringoperation of the excavating machine 10 and (2) swinging the dischargeconveyor 54 into its stowed position for transport. Shafts and hingescould also function adequately for this purpose. The turntable assembly74, however, is preferred because it provides more stable support forthe discharge conveyor 54 and can provide more precise radialdisplacement of the discharge conveyor 54 than can many other pivotmechanisms. The illustrated and preferred turntable assembly 74 includesa table 100 on which the discharge conveyor 54 is mounted, a bearing 102rotatably mounting the table 100 on the base 84, and a drive assembly.The drive assembly has a first portion mounted on the base 84 and asecond portion mounted on the table 100 such that the first and secondportions interact to selectively rotate the table 100 about the bearing102. In the illustrated and preferred embodiment, the first portioncomprises an externally-toothed gear 104 mounted on the base 84coaxially with the bearing 102, and the second portion comprises (1) ahydrostatically-actuated motor 106 which is bolted or otherwise affixedto the upper surface of the table 100, and (2) a drive pinon 108 whichextends downwardly from the table 100 and which meshes with the gear104. Activation of the motor 106 rotates the pinon 108 to drive themotor 106 and table 100 to rotate about the gear 104, therebyhorizontally swinging the discharge conveyor 54.

In addition to being horizontally swingable with respect to the chassis18, the discharge conveyor 54 is also preferably vertically pivotablewith respect to the turntable assembly 74 and chassis 18 to accommodatetrucks of different heights. To this end, a pair of support plates 110extend upwardly from the table 100 and pivotally receive the inlet end64 of the discharge conveyor 54 at a pivot axis 112. Each of a pair ofhydraulic cylinders 114 is pivotally connected to a respective one ofthe side plates 110 at its cylinder end and to the discharge conveyor 54at its rod end at a location intermediate the inlet and discharge endsthereof. Extension or retraction of cylinders 114 accordingly pivots thedischarge conveyor 54 about its axis 112 to raise and lower thedischarge end 66 with respect to the chassis 18.

4. Operation of Excavating Machine

In operation, a narrow trench 116 is cut through rock or another hard orcompacted surface by the rocksaw assembly 14 by rotating the cuttingwheel 38 in the direction of arrow 118 in FIG. 1 while the vehicle 12travels forwardly in the direction of arrow 22. Cylinders 58 areretracted at this time to place the inlet end 60 of the loading conveyor52 on the ground adjacent the cutting wheel 38, and cylinders 94 areretracted to position the turntable assembly 74 and inlet end 64 of thedischarge conveyor 54 on the longitudinal centerline of the loadingconveyor 52 so that the inlet end 64 of the discharge conveyor 54 islocated directly under the discharge end 62 of the loading conveyor 52.Accordingly, excavated materials 120, thrown onto the loading conveyor52 by rotation of the cutting wheel 38, are conveyed forwardly withrespect to the vehicle 12, discharged onto the discharge conveyor 54from the loading conveyor 52, and discharged into the truck T viaoperation of the discharge conveyor 5. As illustrated in FIG. 3, thedischarge conveyor 54 can be rotated anywhere within an arc of about180° by suitable operation of the turntable motor 106 at this timewithout interference from the loading conveyor 52. Due to this fact, anddue to the facts that (1) the discharge conveyor 54 is located on thelongitudinal centerline of the loading conveyor 52, and (2) the loadingconveyor 52 is positioned on the longitudinal centerline of the chassis18, excavated materials 120 can be discharged at any designated positionequidistant from opposed lateral sides of the chassis 18.

Assuming now that the excavating machine 10 is to be transported, thecylinders 36 and 46 are retracted to raise the carriage 30 on the mast32 and to pivot the rocksaw assembly 14 upwardly with respect to thecarriage 30, thereby raising the cutting wheel 38 a sufficient distanceabove the ground for transport. The discharge conveyor 54 is then placedinto a stowed or transport position by positioning it within thedimensional confines of the vehicle 12 in the following manner: First,the cylinders 94 are extended to drive the base 84 along the rails 82from the position illustrated in FIG. 8 to the position illustrated inFIG. 7, thereby offsetting the turntable assembly 74 and dischargeconveyor 54 from the longitudinal centerline of the loading conveyor 52.Then, motor 106 is activated to rotate the table 100 and dischargeconveyor 54 about the base 84 from the position illustrated in FIG. 7 tothe position illustrated in FIG. 6 in which the discharge conveyor 54extends at least substantially in parallel with the loading conveyor 52and in which the discharge end 66 of the discharge conveyor 54 islocated between the inlet and discharge ends 60 and 62 of the loadingconveyor 52. Rotation to this position without interference from theloading conveyor 52 is possible only because of the offset relationshipbetween the turntable assembly 74 and the longitudinal centerline of theloading conveyor 52. This offset relationship also permits extension ofthe cylinders 58 to lower the discharge end 62 of the loading conveyor52 below the level of the inlet end 64 of the discharge conveyor 54 (aposition which otherwise would be prevented by the presence of thedischarge conveyor 54) thereby raising the inlet end 60 of the loadingconveyor 54 to the transport position illustrated in FIG. 5.

Many changes and modifications could be made to the invention withoutdeparting from the spirit thereof. For instance, virtually any diggingimplement could be used in place of the illustrated rocksaw assembly 14.The orientation of the digging implement 14 and the conveyor assembly 16relative to the longitudinal ends of the vehicle 12 could also bereversed. Moreover, the loading conveyor 52 need not receive excavatedmaterials directly from a digging implement 14 and need not bepositioned on the longitudinal centerline of the chassis 18 as shown.Other arrangements than those described and illustrated could also beused to effect transverse and rotational movement of the dischargeconveyor 54 relative to the chassis 18. The scope of these and othermodifications will become apparent from the appended claims.

I claim:
 1. An excavating machine comprising:(A) a portable chassishaving first and second longitudinal ends; (B) a digging implementmounted on said first longitudinal end of said chassis; (C) a loadingconveyor extending longitudinally of said chassis, said loading conveyorhaving an inlet end which receives excavated materials from said diggingimplement and a discharge end which is located in the vicinity of saidsecond longitudinal end of said chassis; and (D) a discharge conveyorhaving an inlet end which receives said excavated materials from saidloading conveyor and having a discharge end, said discharge conveyorbeing mounted on said chassis so as to be rotatable with respect to saidchassis about a vertical axis, said axis being movable laterally withrespect to said chassis, wherein, upon movement of said axis laterallywith respect to said chassis and rotation of said discharge conveyorabout said axis, said discharge conveyor is movable (1) from anoperative position in which said inlet end thereof is located directlyunder said discharge end of said loading conveyor and said discharge endtherefore is positioned beyond said second longitudinal end of saidchassis (2) to a transport position (a) in which said discharge conveyorextends substantially in parallel with said loading conveyor and (b) inwhich said discharge end of said discharge conveyor is located betweensaid inlet and discharge ends of said loading conveyor and between saidfirst and second longitudinal ends said chassis.
 2. An excavatingmachine as defined in claim 1, further comprising a support assemblywhich supports said discharge conveyor on said chassis, said supportassembly including(A) a base which is movable laterally with respect tosaid chassis; and (B) a turntable assembly which supports said dischargeconveyor on said base for rotation about said axis, wherein said base islocated (1) in a first position located on a longitudinal centerline ofsaid loading conveyor when said discharge conveyor is in said operativeposition and (2) in a second position which is offset laterally fromsaid longitudinal centerline when said discharge conveyor is in saidtransport position.
 3. An excavating machine comprising:(A) a portablechassis having first and second longitudinal ends; (B) a diggingimplement mounted on said first longitudinal end of said chassis; (C) aloading conveyor extending longitudinally of said chassis, said loadingconveyor having an inlet end which receives excavated materials fromsaid digging implement and a discharge end which is located in thevicinity of said second longitudinal end of said chassis; (D) adischarge conveyor having an inlet end which receives said excavatedmaterials from said loading conveyor and having a discharge end, saiddischarge conveyor being movable (1) from an operative position in whichsaid inlet end thereof is located directly under said discharge end ofsaid loading conveyor (2) to a transport position (a) in which saiddischarge conveyor extends substantially in parallel with said loadingconveyor and (b) in which said discharge end of said discharge conveyoris located between said inlet and discharge ends of said loadingconveyor; and (E) a support assembly which supports said dischargeconveyor on said chassis, said support assembly including(1) a basewhich is movable laterally with respect to said chassis, and (2) aturntable assembly which supports said discharge conveyor on said basefor rotation about a vertical axis, wherein said base is located (1) ina first position located on a longitudinal centerline of said loadingconveyor when said discharge conveyor is in said operative position and(2) in a second position which is offset laterally from saidlongitudinal centerline when said discharge conveyor is in saidtransport position, wherein said support assembly further comprises asupport frame which presents rails extending transversely of saidchassis, and wherein said base is slidably supported on said rails, andfurther comprising a hydraulic cylinder (1) which is connected to saidbase and to said support frame and (2) which drives said base to slidealong said rails from a first position to a second position.
 4. Anexcavating machine as defined in claim 3, wherein said support assemblyincludes a plate having edge portions forming said rails, and whereinsaid base has L-shaped members depending therefrom which engage saidedge portions.
 5. An excavating machine as defined in claim 2, whereinsaid turntable assembly comprisesa table on which said dischargeconveyor is mounted; a bearing rotatably mounting said table on saidbase; and a drive assembly having a first portion mounted on said baseand a second portion mounted on said table, said first and secondportions of said drive assembly interacting to selectively rotate saidtable about said bearing.
 6. An excavating machine as defined in claim5, wherein said drive assembly comprises (1) a gear which is mounted onsaid base coaxially with said bearing, (2) a motor which is mounted onsaid table, and (3) a pinion which is driven by said motor and whichmeshes with said gear.
 7. An excavating machine as defined in claim 2,wherein said discharge conveyor is pivotable vertically with respect tosaid turntable assembly, and further comprising a hydraulic cylinderwhich is connected to said discharge conveyor and to said turntableassembly and which is pivots said discharge conveyor with respect tosaid turntable assembly.
 8. An excavating machine as defined in claim 2,wherein said loading conveyor is pivotable about a horizontal axis (1)to raise said inlet end thereof from a lowered operative position to araised transport position and (2) to lower said discharge end thereoffrom a raised operative position to a transverse position below a levelof said inlet end of said discharge conveyor.
 9. An excavating machineas defined in claim 1, wherein said digging implement comprises a rocksaw assembly.
 10. An excavating machine comprising:(A) a portablechassis having first and second longitudinal ends; (B) a diggingimplement mounted on said first longitudinal end of said chassis; (C) aloading conveyor extending longitudinally of said chassis, said loadingconveyor having an inlet end which receives excavated materials fromsaid digging implement and a discharge end which is located in thevicinity of said second longitudinal end of said chassis; (D) adischarge conveyor having an inlet end which receives said excavatedmaterials from said loading conveyor and having a discharge end; and (E)a support assembly which supports said discharge conveyor on saidchassis, said support assembly including(1) a support frame, (2) a basewhich is mounted on said support frame and which is movable laterallywith respect to said chassis from a location on a longitudinalcenterline of said loading conveyor to a location which is offsetlaterally from said longitudinal centerline, and (3) a turntableassembly which supports said discharge conveyor on said base forrotation about a vertical axis.
 11. An excavating machine as defined inclaim 10, wherein said support assembly further comprises rails whichare supported on said support frame and upon which said base is slidablymounted, and further comprising a hydraulic cylinder (1) which isconnected to said base and to said support frame and (2) which drivessaid base to slide along said rails from a first position to a secondposition.
 12. An excavating machine as defined in claim 11, wherein saidrails comprise edge portions of said frame and said base has L-shapedbars depending therefrom which engage said edge portions.
 13. Anexcavating machine as defined in claim 10, wherein said turntableassembly comprisesa table on which said discharge conveyor is mounted; abearing rotatably mounting said table on said base; and a drive assemblyhaving a first portion mounted on said base and a second portion mountedon said table, said first and second portions of said drive assemblyinteracting to selectively rotate said table about said bearing.
 14. Amethod comprising:(A) providing an excavating machine having (1) aportable chassis having first and second longitudinal ends, (2) anexcavating machine mounted on said first longitudinal end of saidchassis, (3) a loading conveyor extending longitudinally of saidchassis, said loading conveyor having an inlet end located in thevicinity of said first end of said chassis and having a discharge endlocated in the vicinity of said second longitudinal end of said chassis,and (4) a discharge conveyor having inlet and discharge ends; (B)placing said excavating machine in an operative position in which saiddischarge end of said loading conveyor is located above said inlet endof said discharge conveyor and in which said inlet end of said dischargeconveyor is located on a longitudinal centerline of said loadingconveyor; (C) while said excavating machine is in said operativeposition, (1) excavating materials using said digging implement, (2)feeding excavated materials to said discharge conveyor using saidloading conveyor, and (3) discharging excavated materials from saidexcavating machine using said discharge conveyor; and then (D) placingsaid excavating machine in a transport position by(1) moving saiddischarge conveyor laterally away from said longitudinal centerline ofsaid loading conveyor, and then (2) rotating said discharge conveyorinto a position in which said discharge conveyor extends substantiallyin parallel with said loading conveyor and in which said discharge endthereof is located between said inlet and discharge ends of said loadingconveyor.
 15. A method as defined in claim 14, wherein said moving stepcomprises sliding said discharge conveyor along rails extendingtransversely of said chassis.
 16. A method as defined in claim 15,wherein said rotating step comprises driving a table to rotate about abearing which is supported on a base, said table supporting said inletend of said discharge conveyor, and said base being slidably mounted onsaid rails.
 17. A method as defined in claim 14, further comprising,during said step (C), rotating said discharge conveyor about a verticalaxis (1) from a first position in which said discharge conveyor extendslaterally over a first side of said chassis and said discharge endthereof is positioned a designated distance from a longitudinalcenterline of said loading conveyor, (2) to a second position in whichsaid discharge conveyor extends laterally over a second side of saidchassis and said discharge end thereof is positioned said designateddistance from said longitudinal centerline of said loading conveyor. 18.A method as defined in claim 14, further comprising pivoting saidloading conveyor about a horizonal axis during step (D), thereby raisingsaid inlet end of said loading conveyor from a lowered operativeposition to a raised transport position and lowering said discharge endbelow a level of said inlet end of said discharge conveyor.